改良液氮冻伤法建立易损动脉粥样硬化斑块模型

目的建立改良液氮冻伤法制作动脉粥样硬化(AS)易损斑块(VP)模型,验证改良法是否优于传统的造模方法。方法雄性新西兰白兔24只随机分为改良方法组(A组)和传统方法组(B组)各12只。分别按照改良方法及传统方法造模,6 w末各组随机抽取4只兔子(A1组=4只,B1组=4只)检测斑块形成状况。A组6 w末、B组10 w末剩余兔子(A2组=8只,B2组=8只)以液氮激发斑块破裂。激发48 h后取出右颈总动脉行HE染色及免疫组化检测斑块内基质金属蛋白(MMP)-1水平。不同时间点分别采集空腹静脉血检测兔血脂水平总胆固醇(TC),甘油三酯(TG)及低密度脂蛋白(LDL)及血清超敏C反应蛋白(hs-CRP)水平。结果高脂3 d后兔血脂水平已明显升高,1 w后达基础水平的4¹5倍;血脂变化曲线可见第1周血脂上升最为明显。与基线水平相比,高脂喂养1 w后两组兔血清hs-CRP即明显升高,至激发前进一步升高,激发后hs-CRP较激发前明显升高;各时间点两组间比较无显著性差异。大体观察及HE染色可见6 w末A1组兔已形成明显的AS化斑块,而B1组兔斑块较小;激发后48 h两组兔子的右颈总动脉均可见AS表面内皮损伤,部分形成血栓;两组易损斑块在组织结构上无明显差异,免疫组化染色见两组斑块处均有MMP-1蛋白的大量表达。结论改良液氮冻伤法可构建易损/破裂粥样硬化斑块,较传统方法明显缩短成模时间,节约造模成本,更快速,更高效。     

Degenerative alterations in noradrenergic neurons of the locus coeruleus in Alzheimer’s disease

Mice carrying mutant amyloid-β precursor protein and presenilin-1 genes (APP/PS1 double transgenic mice) have frequently been used in studies of Alzheimer’s disease; however, such studies have focused mainly on hippocampal and cortical changes. The severity of Alzheimer’s disease is known to correlate with the amount of amyloid-β protein deposition and the number of dead neurons in the locus coeruleus. In the present study, we assigned APP/PS1 double transgenic mice to two groups according to age: young mice (5-6 months old) and aged mice (16-17 months old). Age-matched wild-type mice were used as controls. Immunohistochemistry for tyrosine hydroxylase (a marker of catecholaminergic neurons in the locus coeruleus) revealed that APP/PS1 mice had 23% fewer cells in the locus coeruleus compared with aged wild-type mice. APP/PS1 mice also had increased numbers of cell bodies of neurons positive for tyrosine hydroxylase, but fewer tyrosine hydroxylase-positive fibers, which were also short, thick and broken. Quantitative analysis using unbiased stereology showed a significant age-related increase in the mean volume of tyrosine hydroxylase-positive neurons in aged APP/PS1 mice compared with young APP/PS1 mice. Moreover, the mean volume of tyrosine hydroxylase-positive neurons was positively correlated with the total volume of the locus coeruleus. These findings indicate that noradrenergic neurons and fibers in the locus coeruleus are predisposed to degenerative alterations in APP/PS1 double transgenic mice.     

Ruthenium Red Colorimetric and Birefringent Staining of Amyloid-β Aggregates in Vitro and in Tg2576 Mice

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Psoriasis and lasting implications

Psoriasis is a chronic immunological disorder that affects the joints and skin. The disease is strongly correlated with genetic predisposition and environmental factors that can act as triggers of the innate and adaptive immune response. Once this immune response has begun many different signaling factors lead to inflammation and plaques which are visible throughout the body. As psoriasis progresses, it strongly affects the mental and physical health of the individual. This article reviews the different types of psoriasis, genetic and environmental triggers of psoriasis, the molecular progression of psoriasis, and current and future therapies.     

不同他汀类药物标准剂量对稳定性斑块的影响

目的探讨不同他汀类药物标准剂量对稳定性斑块的影响。方法入选经冠状动脉造影和血管内超声检查确定为稳定性斑块的135例患者,分为3组：辛伐他汀20mg组47例,阿托伐他汀20mg组45例,瑞舒伐他汀10mg组43例。随访3-6个月,观察给予不同他汀类药物标准剂量的3组血清低密度脂蛋白-胆固醇（10wdensitvlipoprotein-cholesterol,LDL—C）、高密度脂蛋白-胆固醇（highdensitylipoprotein—cholesterol,HDL．C）、高敏C反应蛋白（high—sensitivityC．reactionprotein,hs—CRP）浓度变化及斑块坏死核所占百分比、斑块体积的动态变化。结果3组血清LDL—C、HDL—C、hs．CRP浓度及斑块坏死核所占百分比、斑块体积的基线资料比较,差异无统计学意义（P〉0．05）。随访3-6个月后,他汀类药物标准剂量治疗的3组血清LDL．C浓度与基线相比均有明显下降,均达标（P〈0．01）,且瑞舒伐他汀最优,阿托伐他汀其次,辛伐他汀最后（P均〈0．01）。辛伐他汀组血清HDL-C浓度与基线比较。差异无统计学意义（P〉0．05）,但阿托伐他汀组、瑞舒伐他汀组明显高于基线,差异有统计学意义（P=0．001．P=0．048）,且两组间比较,差异无统计学意义（P=0．852）。辛伐他汀组血清hs—CRP浓度与基线比较,差异无统计学意义（P〉0．05）,但阿托伐他汀组、瑞舒伐他汀组明显低于基线,差异有统计学意义（P=0．015,P=0．025）．且两组间比较,差异无统计学意义（P=0．411）。通过血管内超声虚拟组织成像技术（intravascularuhrasound—virtualhistology,IVUS—vH）检测,斑块坏死核所占百分比在辛伐他汀组明显高于基线,差异有统计学意义（16．33％-＋15．38％眦7．87％-＋1．04％,P〈0．01）;阿托伐汀组治疗后与基线相比,斑块坏死核所占百分比明显减少,差异有统计学意义（6．64％±3．25％帆7．91％±1．27％,P=0．007）;瑞舒伐他汀组斑块坏死核所占百分比与基线相比,差异无统计学意义（P=0．133）。斑块体积在辛伐他汀组治疗前、后比较,差异无统计学意义（P=O．286）;但阿托伐他汀组、瑞舒伐他汀组斑块体积明显低于基线,差异有统计学意义[（28．65±10．77）mm。vs．（33．31±10．75）mm3,P=0．041;（30．69_＋8．12）mm3ys．（36．337-＋12．15）mm。,P=0．013],且治疗后两组体积比较,差异有统计学意义（P=0．322）。结论不同种类他汀类药物标准剂量对稳定性斑块疗效不同：对于LDL—C,辛伐他汀、阿托伐他汀、瑞舒伐他汀标准剂量治疗后均可达标;阿托伐他汀、瑞舒伐他汀能升高HDL—C,降低hs—CRP;辛伐他汀无遏制斑块向不稳定进展的作用,阿托伐他汀有促进斑块稳定,逆转斑块的作用,瑞舒伐他汀可阻止斑块进展及逆转斑块的作用。     

超声评估颈动脉粥样硬化斑块性质与病理对照分析

目的 探讨超声对颈动脉粥样硬化(CAS)斑块性质判定的准确性及临床应用价值.方法 61例CAS斑块患者均行颈动脉超声检查及颈动脉内膜剥脱术(CEA),标本送病理分析.超声评估血管管腔直径狭窄率,斑块性质(低回声斑块、混合回声斑块、强回声斑块),并与相应的颈动脉内膜病理改变进行对照分析.结果 61例患者中,混合回声斑块34例,低回声斑块25例,强回声斑块2例.93.4％ (57/61)的斑块病理改变为脂质坏死池形成.混合回声斑块和低回声斑块的病理改变中的慢性炎细胞浸润的比例分别为42.6％(26/61)、37.7％(23/61),混合回声斑块的慢性炎细胞浸润较低回声斑块比例高.不连续性纤维帽的斑块比例(52.5％,32/61)较连续性纤维帽的斑块比例高(37.7％,23/61).钙化是强回声斑块的主要病理改变.结论 超声可直观评价CAS斑块性质.超声评价CAS斑块性质为临床诊断提供了客观依据,具有重要的应用价值.     

A review and critique of U.S. EPA's risk assessments for asbestos

U.S. Environmental Protection Agency (EPA) recently conducted a risk assessment for exposure to Libby amphibole asbestos that is precedent-setting for two reasons. First, the Agency has not previously conducted a risk assessment for a specific type of asbestos fiber. Second, the risk assessment includes not only an inhalation unit risk (IUR) for the cancer endpoints, but also a reference concentration (RfC) for nonmalignant disease. In this paper, we review the procedures used by the Agency for both cancer and nonmalignant disease and discuss the strengths and limitations of these procedures. The estimate of the RfC uses the benchmark dose method applied to pleural plaques in a small subcohort of vermiculite workers in Marysville, Ohio. We show that these data are too sparse to inform the exposure–response relationship in the low-exposure region critical for estimation of an RfC, and that different models with very different exposure–response shapes fit the data equally well. Furthermore, pleural plaques do not represent a disease condition and do not appear to meet the EPA's definition of an adverse condition. The estimation of the IUR for cancer is based on a subcohort of Libby miners, discarding the vast majority of lung cancers and mesotheliomas in the entire cohort and ignoring important time-related factors in exposure and risk, including effect modification by age. We propose that an IUR based on an endpoint that combines lung cancer, mesothelioma, and nonmalignant respiratory disease (NMRD) in this cohort would protect against both malignant and nonmalignant disease. However, the IUR should be based on the entire cohort of Libby miners, and the analysis should properly account for temporal factors. We illustrate our discussion with our own independent analyses of the data used by the Agency.